This paper presents long-term scenarios on the development of urban passenger mobility and related carbon dioxide (CO2) emissions by 2050 in global cities that have populations greater than 300,000 on the basis of the International Transport Forum’s new global urban passenger transport model. Results from the policy scenarios analysis show that in the baseline scenario total motorized mobility and related CO2 emissions in cities will grow by 94% and 27% in 2050 compared with 2015. The share of private cars will continue to increase in developing regions while slightly decreasing in developed economies. Policy measures exist to fulfill mobility demand while reducing the carbon intensity of travel. Technology contributes the most to the CO2 mitigation in the most transit-oriented scenarios. Behavioral policies such as fuel tax, lower transit fares, and controlled urban sprawl can bring the additional mitigation efforts required to make cities sustainable and are essential to combat congestion and health issues.